upgrade eslint to v4.8.0
upgrade eslint to v4.8.0

hoverduck/mocha,adamgruber/mocha,boneskull/mocha,mochajs/mocha,hoverduck/mocha,mochajs/mocha,igwejk/mocha,boneskull/mocha,hoverduck/mocha,adamgruber/mocha,outsideris/mocha,mochajs/mocha,outsideris/mocha,hoverduck/mocha,adamgruber/mocha,boneskull/mocha,igwejk/mocha